GudWater guides https://gudwater.us/ Independent, research-backed water filter guides. We check NSF/ANSI certifications and EPA data so you buy a filter for the problem you actually have. en-us Reverse Osmosis vs. Carbon Filters vs. Pitchers: Which Should You Buy?https://gudwater.us/guides/reverse-osmosis-vs-carbon-filters/https://gudwater.us/guides/reverse-osmosis-vs-carbon-filters/Wed, 07 Oct 2026 12:00:00 GMTA plain comparison of reverse osmosis, under-sink carbon and pitcher filters: what each reduces, upkeep, water waste and cost, plus a quick way to decide which one fits your water. Do Water Filters Remove PFAS? What the Research Showshttps://gudwater.us/guides/do-water-filters-remove-pfas/https://gudwater.us/guides/do-water-filters-remove-pfas/Wed, 07 Oct 2026 12:00:00 GMTReverse osmosis and two-stage filters removed 94% or more of PFAS in a Duke and NC State study, while carbon pitchers were inconsistent. Here's what that means, plus the current EPA PFAS rules. NSF Water Filter Certifications Explained: 42, 53, 58, 401 and Morehttps://gudwater.us/guides/nsf-water-filter-certifications/https://gudwater.us/guides/nsf-water-filter-certifications/Wed, 07 Oct 2026 12:00:00 GMTWhat NSF/ANSI 42, 53, 58, 401, 44, 55 and 244 mean on a water filter box, why the standard number alone isn't enough, and how to check a model's certified claims in two minutes. Lead in Tap Water: How to Test for It and Which Filters Reduce Ithttps://gudwater.us/guides/lead-in-drinking-water/https://gudwater.us/guides/lead-in-drinking-water/Wed, 07 Oct 2026 12:00:00 GMTThere is no known safe level of lead exposure. Learn where lead in tap water comes from, how to test, the new 10 ppb federal action level, and how to pick a filter certified for lead. How to Read Your Water Quality Report in 10 Minuteshttps://gudwater.us/guides/how-to-read-water-quality-report/https://gudwater.us/guides/how-to-read-water-quality-report/Wed, 07 Oct 2026 12:00:00 GMTYour water utility publishes a Consumer Confidence Report every year. Here's how to find yours, what MCL, MCLG and action level mean, and how to turn the numbers into the right filter choice. Is Alkaline Water Worth It? What the Evidence Actually Sayshttps://gudwater.us/guides/alkaline-water-evidence/https://gudwater.us/guides/alkaline-water-evidence/Wed, 07 Oct 2026 12:00:00 GMTAlkaline and ionized water (including Kangen machines) are marketed with big health claims. Systematic reviews find little good human evidence. Here's what the studies show and what to buy instead.